Bacteria, like other organisms in nature, depend on one
another for survival, particularly in hostile conditions.
The above image shows various bacteria from an environment
where there is no oxygen and where microbes make methane.

This particular environment is called a methane-producing
biomass digester which scientists have set up in the lab to
study such organisms.

Some of the microbes in this picture are called
methanogens (fancy name for methane makers). Methanogens
live where there is no oxygen. Like other microbes that grow
without oxygen, methanogens are called anaerobes.

The methane produced by this community is used for fuel,
a flammable gas known as natural gas used to heat your
home.

Bacteria often like to live on surfaces. The bacteria and
other microbes that live on surfaces make up a slimy surface
people generally refer to as slime. Since this slim consists
of live creatures, it is called a biofilm.